The FDA has approved a second drug for fibrodysplasia ossificans progressiva, an ultra rare genetic disease in which muscle, tendon and ligament gradually turn into bone. Patients effectively grow a second skeleton, one that locks joints permanently and generally cannot be removed surgically, because cutting it out tends to trigger more bone formation.
The drug is Pasatru, generic name garetosmab-grts, made by Regeneron. The FDA approved it to reduce new heterotopic ossification, the term for bone forming outside the skeleton, and to reduce clinician-assessed disease flare-ups in adults. It carried Breakthrough Therapy, Fast Track, Orphan Drug and Priority Review designations.
